Blood flow through the vessels

Question 1

Can fluid flow if there is not a drop in pressure moving from the arterial side to the venous side?

Answer 1

Only if there is no resistance, which there is always frictional resistance in the vessels

Question 2

What three factors increase resistance in the vessel?

Answer 2

Decreasing the radius
Increased length of tube
Increased viscosity of the blood (all of these increase frictional drag)

Question 3

What is the pressure drop in our circulatory system?

Answer 3

The difference between MAP and CVP

Question 4

What term describes vascular distensibility, synonymous with compliance of the lungs?

Answer 4

Capacitance is the ability of the vessel to increase volume with increasing transmural pressure
C= change in volume/change in pressure

Question 5

What two factors are directly proportional to flow through a tube?

Answer 5

Hydrostatic pressure

Radius

Question 6

What is the most important factor in determining blood flow?

Answer 6

Radius (raised to the fourth power, thus small changes impact drastically)

Question 7

Why is it more beneficial for our vasculature to be set up parallel verses a series?

Answer 7

In parallel vasculature there is less total resistance

Question 8

How can series vasculature and parallel vasculature be described mathematically?

Answer 8

Series circulation is the sum of the individual resistances where as parallel circulation is the sum of the reciprocal of the individual resistances

Question 9

Define conductance.

Answer 9

How easily blood flows through a tube for a given pressure difference across both end of the tube

Question 10

Knowing what we know about parallel circulation, what would happened to the resistance of blood flow in a person who had a recent amputation?

Answer 10

The total resistance would increase because a parallel circuit was lost with the amputation

Question 11

What does the Reynold’s number predict?

Answer 11

When laminar blood flow would become turbulent

Question 12

What types of currents cause increased resistance to flow leading to stasis and plaques?

Answer 12

Eddy Current

Question 13

Does the autonomic nervous system innervate the vasculature?

Answer 13

SNS innervates the vasculature ONLY with the exception of the PSNS innervating only the brains vasculature

Question 14

Define vascular distensibility.

Answer 14

The percent increase in vessel volume for a given change in pressure

Question 15

How does the SNS impact the vasculature?

Answer 15

SNS constricts the vasculature, increasing the pressure within the vessel. However, the SNS does not change the compliance

Question 16

What mechanism causes aneurysms to enlarge?

Answer 16

The kinetic energy decreases causing the pressure energy to increase resulting in more lateral wall pressure

Question 17

In an aneurysm, how does the wall tension increase in order to keep up with an increasing radius and curvature?

Answer 17

Increase wall tension by increasing wall thickness

Question 18

According to LaPlace law, if pressure inside a sphere is constant, how will an increase in radius affect tension?

Answer 18

The wall tension increases when radius increases

Question 19

A change in volume for a given change in pressure is equal to characteristic of the vessels?

Answer 19

Vascular capacatance

Question 20

How do we determine vascular distensibility?

Answer 20

change in volume divided by volume multiplied by 100 and divide the whole numerator by the change in pressure, this is beneficial to use because there are various types of vessels in the vasculature

Question 21

Reflex control of blood flow is know as?

Answer 21

Autoregulation